text: A large share of water supply systems around the world are intermittent; in other words, intermittent water supply is a norm. About 1.3 billion people have a piped supply that is intermittent, including large populations in Africa, Asia, and Latin America. This does not include those who do not get piped water at all, about 2.7 billion people. Countries with intermittent supply in some areas and continuous supply in others include India and South Africa. In India, various cities are at various stages of constructing 24/7 supply systems, such as Chandigarh, Delhi, Shimla, and Coimbatore. In Cambodia, Phnom Penh increased coverage from 25% to 85% and duration from 10 to 24 hours a day between 1993 and 2004.